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index 79c5f69d421399091b7ee6f71339505edf15ce0c..f56dfcabb96d1510abfd61a13c36135f3824b744 100644 (file)
This program is usually not what the end user wants to run directly.
Most end users want to use one of the existing frontend programs,
which parses a specific type of foreign source and feeds the contents
-stored there to 'git-fast-import'.
+stored there to 'git fast-import'.
fast-import reads a mixed command/data stream from standard input and
writes one or more packfiles directly into the current repository.
with the newly imported data.
The fast-import backend itself can import into an empty repository (one that
-has already been initialized by 'git-init') or incrementally
+has already been initialized by 'git init') or incrementally
update an existing populated repository. Whether or not incremental
imports are supported from a particular foreign source depends on
the frontend program in use.
not contain the old commit).
--max-pack-size=<n>::
- Maximum size of each output packfile, expressed in MiB.
- The default is 4096 (4 GiB) as that is the maximum allowed
- packfile size (due to file format limitations). Some
- importers may wish to lower this, such as to ensure the
- resulting packfiles fit on CDs.
+ Maximum size of each output packfile.
+ The default is unlimited.
--big-file-threshold=<n>::
Maximum size of a blob that fast-import will attempt to
set of marks. If a mark is defined to different values,
the last file wins.
+--relative-marks::
+ After specifying --relative-marks= the paths specified
+ with --import-marks= and --export-marks= are relative
+ to an internal directory in the current repository.
+ In git-fast-import this means that the paths are relative
+ to the .git/info/fast-import directory. However, other
+ importers may use a different location.
+
+--no-relative-marks::
+ Negates a previous --relative-marks. Allows for combining
+ relative and non-relative marks by interweaving
+ --(no-)-relative-marks= with the --(import|export)-marks=
+ options.
+
+--cat-blob-fd=<fd>::
+ Specify the file descriptor that will be written to
+ when the `cat-blob` command is encountered in the stream.
+ The default behaviour is to write to `stdout`.
+
--export-pack-edges=<file>::
After creating a packfile, print a line of data to
<file> listing the filename of the packfile and the last
This information may be useful after importing projects
whose total object set exceeds the 4 GiB packfile limit,
as these commits can be used as edge points during calls
- to 'git-pack-objects'.
+ to 'git pack-objects'.
--quiet::
Disable all non-fatal output, making fast-import silent when it
Parallel Operation
------------------
-Like 'git-push' or 'git-fetch', imports handled by fast-import are safe to
+Like 'git push' or 'git fetch', imports handled by fast-import are safe to
run alongside parallel `git repack -a -d` or `git gc` invocations,
-or any other Git operation (including 'git-prune', as loose objects
+or any other Git operation (including 'git prune', as loose objects
are never used by fast-import).
fast-import does not lock the branch or tag refs it is actively importing.
prints a warning message. fast-import will always attempt to update all
branch refs, and does not stop on the first failure.
-Branch updates can be forced with \--force, but its recommended that
+Branch updates can be forced with \--force, but it's recommended that
this only be used on an otherwise quiet repository. Using \--force
is not necessary for an initial import into an empty repository.
+
An example value is ``Tue Feb 6 11:22:18 2007 -0500''. The Git
parser is accurate, but a little on the lenient side. It is the
-same parser used by 'git-am' when applying patches
+same parser used by 'git am' when applying patches
received from email.
+
Some malformed strings may be accepted as valid dates. In some of
created by fast-import. There is no way to specify a different time or
timezone.
+
-This particular format is supplied as its short to implement and
+This particular format is supplied as it's short to implement and
may be useful to a process that wants to create a new commit
right now, without needing to use a working directory or
-'git-update-index'.
+'git update-index'.
+
If separate `author` and `committer` commands are used in a `commit`
the timestamps may not match, as the system clock will be polled
standard output. This command is optional and is not needed
to perform an import.
+`cat-blob`::
+ Causes fast-import to print a blob in 'cat-file --batch'
+ format to the file descriptor set with `--cat-blob-fd` or
+ `stdout` if unspecified.
+
+`feature`::
+ Require that fast-import supports the specified feature, or
+ abort if it does not.
+
+`option`::
+ Specify any of the options listed under OPTIONS that do not
+ change stream semantic to suit the frontend's needs. This
+ command is optional and is not needed to perform an import.
+
`commit`
~~~~~~~~
Create or update a branch with a new commit, recording one logical
Here `<committish>` is any of the following:
* The name of an existing branch already in fast-import's internal branch
- table. If fast-import doesn't know the name, its treated as a SHA-1
+ table. If fast-import doesn't know the name, it's treated as a SHA-1
expression.
* A mark reference, `:<idnum>`, where `<idnum>` is the mark number.
* A complete 40 byte or abbreviated commit SHA-1 in hex.
* Any valid Git SHA-1 expression that resolves to a commit. See
- ``SPECIFYING REVISIONS'' in linkgit:git-rev-parse[1] for details.
+ ``SPECIFYING REVISIONS'' in linkgit:gitrevisions[7] for details.
The special case of restarting an incremental import from the
current branch value should be written as:
'M' SP <mode> SP <dataref> SP <path> LF
....
+
-Here `<dataref>` can be either a mark reference (`:<idnum>`)
+Here usually `<dataref>` must be either a mark reference (`:<idnum>`)
set by a prior `blob` command, or a full 40-byte SHA-1 of an
-existing Git blob object.
+existing Git blob object. If `<mode>` is `040000`` then
+`<dataref>` must be the full 40-byte SHA-1 of an existing
+Git tree object or a mark reference set with `--import-marks`.
Inline data format::
The data content for the file has not been supplied yet.
* `160000`: A gitlink, SHA-1 of the object refers to a commit in
another repository. Git links can only be specified by SHA or through
a commit mark. They are used to implement submodules.
+* `040000`: A subdirectory. Subdirectories can only be specified by
+ SHA or through a tree mark set with `--import-marks`.
In both formats `<path>` is the complete path of the file to be added
(if not already existing) or modified (if already existing).
If an `LF` or double quote must be encoded into `<path>` shell-style
quoting should be used, e.g. `"path/with\n and \" in it"`.
+Additionally, in `040000` mode, `<path>` may also be an empty string
+(`""`) to specify the root of the tree.
+
The value of `<path>` must be in canonical form. That is it must not:
* contain an empty directory component (e.g. `foo//bar` is invalid),
complete set of bytes which normally goes into such a signature.
If signing is required, create lightweight tags from within fast-import with
`reset`, then create the annotated versions of those tags offline
-with the standard 'git-tag' process.
+with the standard 'git tag' process.
`reset`
~~~~~~~
The mark command is optional here as some frontends have chosen
to generate the Git SHA-1 for the blob on their own, and feed that
-directly to `commit`. This is typically more work than its worth
+directly to `commit`. This is typically more work than it's worth
however, as marks are inexpensive to store and easy to use.
`data`
inform the reader when the `checkpoint` has been completed and it
can safely access the refs that fast-import updated.
+`cat-blob`
+~~~~~~~~~~
+Causes fast-import to print a blob to a file descriptor previously
+arranged with the `--cat-blob-fd` argument. The command otherwise
+has no impact on the current import; its main purpose is to
+retrieve blobs that may be in fast-import's memory but not
+accessible from the target repository.
+
+....
+ 'cat-blob' SP <dataref> LF
+....
+
+The `<dataref>` can be either a mark reference (`:<idnum>`)
+set previously or a full 40-byte SHA-1 of a Git blob, preexisting or
+ready to be written.
+
+output uses the same format as `git cat-file --batch`:
+
+====
+ <sha1> SP 'blob' SP <size> LF
+ <contents> LF
+====
+
+This command can be used anywhere in the stream that comments are
+accepted. In particular, the `cat-blob` command can be used in the
+middle of a commit but not in the middle of a `data` command.
+
+`feature`
+~~~~~~~~~
+Require that fast-import supports the specified feature, or abort if
+it does not.
+
+....
+ 'feature' SP <feature> ('=' <argument>)? LF
+....
+
+The <feature> part of the command may be any one of the following:
+
+date-format::
+export-marks::
+relative-marks::
+no-relative-marks::
+force::
+ Act as though the corresponding command-line option with
+ a leading '--' was passed on the command line
+ (see OPTIONS, above).
+
+import-marks::
+ Like --import-marks except in two respects: first, only one
+ "feature import-marks" command is allowed per stream;
+ second, an --import-marks= command-line option overrides
+ any "feature import-marks" command in the stream.
+
+cat-blob::
+ Ignored. Versions of fast-import not supporting the
+ "cat-blob" command will exit with a message indicating so.
+ This lets the import error out early with a clear message,
+ rather than wasting time on the early part of an import
+ before the unsupported command is detected.
+
+`option`
+~~~~~~~~
+Processes the specified option so that git fast-import behaves in a
+way that suits the frontend's needs.
+Note that options specified by the frontend are overridden by any
+options the user may specify to git fast-import itself.
+
+....
+ 'option' SP <option> LF
+....
+
+The `<option>` part of the command may contain any of the options
+listed in the OPTIONS section that do not change import semantics,
+without the leading '--' and is treated in the same way.
+
+Option commands must be the first commands on the input (not counting
+feature commands), to give an option command after any non-option
+command is an error.
+
+The following commandline options change import semantics and may therefore
+not be passed as option:
+
+* date-format
+* import-marks
+* export-marks
+* cat-blob-fd
+* force
+
Crash Reports
-------------
If fast-import is supplied invalid input it will terminate with a
When committing fixups, consider using `merge` to connect the
commit(s) which are supplying file revisions to the fixup branch.
-Doing so will allow tools such as 'git-blame' to track
+Doing so will allow tools such as 'git blame' to track
through the real commit history and properly annotate the source
files.
~~~~~~~~~~~~~~~~~~~~~~~~~
If you are repacking very old imported data (e.g. older than the
last year), consider expending some extra CPU time and supplying
-\--window=50 (or higher) when you run 'git-repack'.
+\--window=50 (or higher) when you run 'git repack'.
This will take longer, but will also produce a smaller packfile.
You only need to expend the effort once, and everyone using your
project will benefit from the smaller repository.
projects with 2,000+ branches and 45,114+ files in a very limited
memory footprint (less than 2.7 MiB per active branch).
+Signals
+-------
+Sending *SIGUSR1* to the 'git fast-import' process ends the current
+packfile early, simulating a `checkpoint` command. The impatient
+operator can use this facility to peek at the objects and refs from an
+import in progress, at the cost of some added running time and worse
+compression.
Author
------